The present invention relates generally to a consumable-article detecting apparatus that is used for an image forming apparatus and detects a consumable article, such as a developer (e.g., toner), and more particularly to a consumable-article detecting apparatus, method and program, which detect toner's physical properties, used in an electrophotographic image forming apparatus, and the image forming apparatus having the consumable-article detecting apparatus.
The present invention is suitable, for example, for an electrophotographic image forming apparatus, such as a printer, a facsimile machine, and a copier. The “electrophotographic image forming apparatus,” as used herein, means an apparatus that utilizes the Carson process disclosed in U.S. Pat. No. 2,297,691, e.g., typically a laser printer or a non-impact image forming apparatus that adheres toner to a recording medium, such as a printing paper and an OHP film, for recording.
The laser printers among the electrophotographic recording apparatuses are fast, high-resolution and high-quality apparatuses, and are increasingly demanded along the recent office automation. With the increased demands, the laser printers are required to have a more improved printing quality, durability and maintainability.
The laser printer generally includes a photosensitive drum and an optical unit that forms a latent image on the photosensitive drum through exposure. The photosensitive drum is charged negative uniformly by a precharger, exposed by a laser beam emitted from the optical unit, and forms the latent image after a portion to which the developer is adhered is discharged. The latent image is visualized as a toner image via a developing unit, and the toner image is transferred onto a printing paper by a transfer unit. A fixing unit fixes the toner image transferred onto the printing paper, and then the printing paper is ejected.
The recent mainstream is a print-unit laser printer that incorporates a toner cartridge, the photosensitive drum, the development unit etc. into a print unit as a printing member. The print-unit system enables a user to exchange the print unit and to easily restore the printing quality when the printing quality of the laser printer lowers after the long-term use. This system dispenses with a specific maintenance person for maintenance, and enables a user to easily and conveniently maintain the printer by himself. When it is unnecessary to exchange the entire print unit, the printing quality can easily be recovered by exchanging a toner cartridge in the print unit.
As discussed above, the laser printer uses optimally designed print unit, toner etc. Laser-printer manufactures generally manufacture and sell print units suitable for their laser printers. The manufactures fully inspect and study the adaptabilities of their print units as so-called genuine products to their laser printers: The laser printer equipped with the corresponding print unit can exhibit its maximum printing performance, such as high resolution and high quality, with no transferring and fixing problems.
For example, one proposed developing unit stops agitating recycle toner and refilling the recycle toner to a developer agitator when detecting a predetermined condition in exchanging the developer, thereby preventing excessive refilling of the toner (see, for example, Japanese Patent Application, Publication No. 2002-341634). Another proposed printer identifies an unauthorized recyclable toner cartridge to exclude its use (see, for example, Japanese Patent Application, Publication No. 2001-215779). Still another printer solves a problem of the uncontrollability of the toner concentration when a toner concentration sensor indicates an abnormal output value, because the charge amount of the developer initially put in the developing unit drastically varies due to the ambient conditions in the maintenance of the developer (see, for example, Japanese Patent Application, Publication No. 10-333418).
A print unit and a toner cartridge equipped with an IC chip that can store information have reduced to practice. A user can recognize the exchange time and information of whether it is time to exchange the print unit by storing, in the IC chip, control information, such as printing number and use time.
However, recently, non-genuine or universal products that are not the genuine products have frequently been sold. The non-genuine print units or so-called pirated articles are those which a third party manufactures and sells without an authorization of the original manufacturer. The adaptability between the non-genuine product and the laser printer is not usually fully studied and an application of the non-genuine product to the laser printer would deteriorate the printing quality and transferring and fixing faults.
In addition, non-genuine toner can be used rather than a non-genuine print unit. When the non-genuine toner is put in a toner cartridge after the genuine toner runs short in the toner cartridge, the printing quality can deteriorate and the transferring and fixing faults can occur.
For example, when a printer that has a developing roller as a magnet roller uses more magnetic non-genuine toner than the genuine toner, the attraction force of the developing roller increases and the printing concentration is thinner than the normal one. Conversely, when the printer uses less magnetic non-genuine toner than the genuine toner, the attraction force of the development roller decreases and the printing concentration is thicker than the normal one.
When these non-genuine products are manufactured and sold, the genuine printer manufacture suffers from reduced sales amount and profit, and should arduously handle users' complaints, such as fault reports and repair requests, when the above faults occur. It is conceivable to detect the non-genuine products by using the above IC chips, but this method makes the print unit and toner cartridge expensive. In addition, this method can detect the non-genuine print unit and toner cartridge, but does not work when non-genuine toner is put in the genuine print unit and toner cartridge instead of the genuine toner.